Security system for electronic device

ABSTRACT

An antitheft system is provided for an electronic apparatus including a television receiver and a DVD recorder connected via an apparatus control line. The DVD recorder includes a non-volatile memory for previously storing a password. The television receiver includes a non-volatile memory for previously storing the password and a controller. The controller requests the DVD recorder to transmit the password stored in the non-volatile memory when the television receiver is activated or started up, and receives the password from the DVD recorder. The controller further compares the received password with the password stored in the non-volatile memory, and starts an operation of the television receiver when the passwords coincide with each other.

TECHNICAL FIELD

The present invention relates to a security system for use in aplurality of electronic apparatuses, such as a television receiver and aDVD recorder communicating with each other, and relates to theelectronic apparatuses.

RELATED PRIOR ART

As a prior art for preventing an electronic apparatus from being stolen,for example, the following antitheft apparatus is disclosed in Patentdocument 1. For example, in order to prevent theft of an audioequipment, a password is previously set and memorized in a non-volatilememory. A user is requested to input the password next time when a powersupply is turned on. The power supply is turned on as usual when theinputted password coincides with the password memorized in thenon-volatile memory. The audio equipment is not operated when thepasswords are different from each other. In the foregoing apparatus, amethod of reading the password has been improved so as to enhance thesecurity.

FIG. 2 shows an antitheft apparatus disclosed in the Patent document 1according to the prior art. In FIG. 2, the antitheft apparatus includesa microprocessor 101 for controlling operation of an audio equipment103, a non-volatile memory 102 for storing information of apredetermined system, and the audio equipment 103.

The microprocessor 101 provides a user with a setting menu forpreviously setting the password at the time of turning on the powersupply, on a screen. The microprocessor 101 then memorizes and registersthe password inputted by the user in the setting menu in thenon-volatile memory 102. When the user turns on the power supply of theaudio equipment 103 after the registration of the password, themicroprocessor 101 displays a password input screen before operating theaudio equipment 103, and asks the user to input the password. Themicroprocessor 101 operates the audio equipment 103 as usual when theinputted password coincides with the password memorized in thenon-volatile memory 102. On the other hand, when the passwords aredifferent from each other, the microprocessor 101 stops the operation ofthe audio equipment 103 in order to prevent theft of the apparatus. Theantitheft apparatus is provided with an additional device so that thepassword memorized in the non-volatile memory 102 is not easily readout.

Patent document 1 is Japanese patent laid-open publication No.H02-042823.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

However, the antitheft apparatus according to the prior art requires auser to input the password every time when the user turns on the powersupply of the audio equipment 103. This leads to that the antitheftapparatus forces the user into a bothersome operation. Further, theapparatus has a problem that only a person who registered the passwordcould operate the audio equipment 103.

Therefore, an essential object of the present invention is to solve theaforementioned problems, and to provide a security system for use in anelectronic apparatus and the electronic apparatus capable of enhancingsecurity in order to prevent theft and the like without requiring theuser to input the password every time when a power supply of theelectronic apparatus is turned on.

According to the first aspect of the present invention, there isprovided a security system for use in a plurality of electronicapparatuses including a first electronic apparatus and a secondelectronic apparatus connected to each other via an apparatus controlline. The second electronic apparatus comprises a second storage device.The second storage device previously stores a password. The firstelectronic apparatus comprises a first storage device and a controldevice. The first storage device previously stores the password. Thecontrol device requests the second electronic apparatus to transmit thepassword stored in the second storage device at activation of the firstelectronic apparatus, receives the password from the second electronicapparatus, compares the received password with the password stored inthe first storage device, and executes a security function so as tostart an operation of the first electronic apparatus when the passwordscoincide with each other.

In the above-mentioned security system, the control device compares thereceived password with the password stored in the first storage device,and executes the security function so as to stop the operation of thefirst electronic apparatus when the passwords do not coincide with eachother.

In addition, in the above-mentioned security system, the firstelectronic apparatus further comprises a display device and an inputdevice. The display device displays a message to a user. The inputdevice inputs the password. The control device compares the receivedpassword with the password stored in the first storage device, displaysa request of inputting the password to a user on the display device whenthe passwords do not coincide with each other, compares the passwordinputted by the user using the input device with the password stored inthe first storage device, and starts the operation of the firstelectronic apparatus when the passwords coincide with each other.

Further, in the above-mentioned security system, the control devicecompares the password inputted by the user with the password stored inthe first storage device, and stops the operation of the firstelectronic apparatus when the passwords do not coincide with each other.

Still further, in the above-mentioned security system, the controldevice compares the password inputted by the user a predetermined numberof times of more than two with the password stored in the first storagedevice, and stops the operation of the first electronic apparatus whenthe passwords do not coincide with each other.

In addition, in the above-mentioned security system, the firstelectronic apparatus further comprises a third storage device. The thirdstorage device previously stores a special password other than thepassword. The control device compares the inputted password with thespecial password stored in the third storage device, and starts theoperation of the first electronic apparatus when the passwords coincidewith each other.

Further, in the above-mentioned security system, the first electronicapparatus further comprises a first detecting device and a seconddetecting device. The first detecting device detects whether or not thesecond electronic apparatus is connected to the first electronicapparatus via the apparatus control line. The second detecting devicedetects whether or not the second electronic apparatus has the securityfunction using a control signal of the apparatus control line when thefirst detecting device detects that the second electronic apparatus isconnected to the first electronic apparatus. The control device executesthe processings of the first detecting device and the second detectingdevice during operation of the first electronic apparatus.

Still further, in the above-mentioned security system, the controldevice stops the processing of the security function, and starts anordinary operation of the first electronic apparatus when the firstdetecting device detects that the second electronic apparatus is notconnected to the first electronic apparatus.

In addition, in the above-mentioned security system, the control devicestops the processing of the security function, and starts the ordinaryoperation of the first electronic apparatus when the second detectingdevice detects that the second electronic apparatus does not have thesecurity function.

According to the second aspect of the present invention, there isprovided a first electronic apparatus provided in a security system foruse in a plurality of electronic apparatuses including a firstelectronic apparatus and a second electronic apparatus connected to eachother via an apparatus control line. The second electronic apparatuscomprises a second storage device. The second storage device previouslystores a password. The first electronic apparatus comprises a firststorage device and a control device. The first storage device previouslystores the password. The control device requests the second electronicapparatus to transmit the password stored in the second storage device,receives the password from the second electronic apparatus when thefirst electronic apparatus is activated or started up, compares thereceived password with the password stored in the first storage device,and executes a security function so as to start an operation of thefirst electronic apparatus when the passwords coincide with each other.

In the above-mentioned electronic apparatus for a security system, thecontrol device compares the received password with the password storedin the first storage device, and executes the security function so as tostop the operation of the first electronic apparatus when the passwordsdo not coincide with each other.

In addition, in the above-mentioned electronic apparatus for a securitysystem, the first electronic apparatus further comprises a displaydevice and an input device. The display device displays a message to auser. The input device inputs the password. The control device comparesthe received password with the password stored in the first storagedevice, displays a request of inputting the password to a user on thedisplay device when the passwords do not coincide with each other,compares the password inputted by the user using the input device withthe password stored in the first storage device, and starts theoperation of the first electronic apparatus when the passwords coincidewith each other.

Further, in the above-mentioned electronic apparatus for a securitysystem, the control device compares the password inputted by the userwith the password stored in the first storage device, and stops theoperation of the first electronic apparatus when the passwords do notcoincide with each other.

Still further, in the above-mentioned electronic apparatus for asecurity system, the control device compares the password inputted bythe user a predetermined number of times of more than two with thepassword stored in the first storage device, and stops the operation ofthe first electronic apparatus when the passwords do not coincide witheach other.

In addition, in the above-mentioned electronic apparatus for a securitysystem, the first electronic apparatus further comprises a third storagedevice. The third storage device previously stores a special passwordother than the password. The control device compares the inputtedpassword with the special password stored in the third storage device,and starts the operation of the first electronic apparatus when thepasswords coincide with each other.

Further, in the above-mentioned electronic apparatus for a securitysystem, the first electronic apparatus further comprises a firstdetecting device and a second detecting device. The first detectingdevice detects whether or not the second electronic apparatus isconnected to the first electronic apparatus via the apparatus controlline. The second detecting device detects whether or not the secondelectronic apparatus has the security function using a control signal ofthe apparatus control line when the first detecting device detects thatthe second electronic apparatus is connected to the first electronicapparatus. The control device executes the processings of the firstdetecting device and the second detecting device during activation ofthe first electronic apparatus.

Still further, in the above-mentioned electronic apparatus for asecurity system, the control device stops the processing of the securityfunction, and starts an ordinary operation of the first electronicapparatus when the first detecting device detects that the secondelectronic apparatus is not connected to the first electronic apparatus.

In addition, in the above-mentioned electronic apparatus for a securitysystem, the control device stops the processing of the securityfunction, and starts the ordinary operation of the first electronicapparatus when the second detecting device detects that the secondelectronic apparatus does not have the security function.

EFFECT OF THE INVENTION

Therefore, according to the security system for use in the electronicapparatus of the present invention, the password is registered in thestorage means of the electronic apparatus used as the connectedauxiliary apparatus in the security system for use in the plurality ofelectronic apparatuses connected via an apparatus control line so thatthe password can be confirmed when the electronic apparatus used as themain apparatus is activated or started up. As far as the apparatuscontrol line is connected, when the passwords coincide with each otherbetween the electronic apparatus used as the main apparatus and theelectronic apparatus used as the auxiliary apparatus, the user canactivate the electronic apparatus in a manner similar to that of theprocessing usually executed when the power supply is turned on. Theelectronic apparatus used as the main apparatus cannot be activated orstarted up when the electronic apparatus used as the auxiliary apparatusis not connected. As a result, even if the electronic apparatus used asthe main apparatus is stolen, it is not possible to activate the same.Accordingly, the theft can be prevented without forcing the user intosuch a bothersome operation as the input of the password. Further, thesystem according to the present invention can be effectively realizedwithout almost increasing the cost.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating a configuration of a securitysystem including a television receiver 201 and a DVD recorder 205according to a preferred embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of an antitheftapparatus according to a prior art.

FIG. 3 is a sequence diagram illustrating a communication procedure P1between a controller 202 and a controller 206 of FIG. 1.

FIG. 4 is a sequence diagram illustrating a communication procedure P2between the controller 202 and the controller 206 of FIG. 1.

FIG. 5 is a sequence diagram illustrating a communication procedure P3between the controller 202 and the controller 206 of FIG. 1.

FIG. 6 is a sequence diagram illustrating a communication procedure P4between the controller 202 and the controller 206 of FIG. 1.

FIG. 7 is a flow chart illustrating a first processing executed by thecontroller 202 of FIG. 1 when a power supply is turned on aftershipment.

FIG. 8 is a flow chart illustrating a security function confirmationprocessing (Step S9) which is a subroutine of FIG. 7.

FIG. 9 is a flow chart illustrating a first part of an apparatus controlprocessing executed by the controller 202 of FIG. 1.

FIG. 10 is a flow chart illustrating a second part of the apparatuscontrol processing executed by the controller 202 of FIG. 1.

FIG. 11 is a flow chart illustrating a third part of the apparatuscontrol processing executed by the controller 202 of FIG. 1

FIG. 12 is a flow chart illustrating a first part of a processingexecuted when an owner ID is re-registered (Step S28) which is asubroutine of FIG. 9.

FIG. 13 is a flow chart illustrating a second part of the processingexecuted when the owner ID is re-registered (Step S28) which is thesubroutine of FIG. 9.

FIG. 14 is a flow chart illustrating a third part of the processingexecuted when the owner ID is re-registered (Step S28) which is thesubroutine of FIG. 9.

FIG. 15 is a flow chart illustrating a modified example of theprocessing of FIG. 10.

FIG. 16 is a flow chart illustrating a modified example of theprocessing of FIG. 11.

FIG. 17 is a flow chart illustrating a modified example of theprocessing of FIG. 12.

FIG. 18 is a front view illustrating a screen D1 for an automatic set-upat start, which is displayed in a processing of Step S1 of FIG. 7.

FIG. 19 is a front view illustrating a screen D2 for registration whenthe power supply is initially turned on, which is displayed in aprocessing of Step S2 of FIG. 7.

FIG. 20 is a front view illustrating a screen D3 for (first)confirmation of use of a security option, which is displayed in aprocessing of Step S8 of FIG. 7.

FIG. 21 is a front view illustrating a screen D4 for (second)confirmation of use of a security option, which is displayed in aprocessing of Step S14 of FIG. 7.

FIG. 22 is a front view illustrating a screen D5 for (third)confirmation of use of a security option, which is displayed in aprocessing of Step S15 of FIG. 7.

FIG. 23 is a front view illustrating a screen D6 for (fourth)confirmation of use of a security option, which is displayed in aprocessing of Step S19 of FIG. 7.

FIG. 24 is a front view illustrating a screen D7 for (fifth)confirmation of use of a security option, which is displayed in aprocessing of Step S12 of FIG. 7.

FIG. 25 is a front view illustrating a screen D8 for a (first)notification that the security function is operated due to thecancellation of the apparatus connection, which is displayed in aprocessing of Step S41 of FIG. 11.

FIG. 26 is a front view illustrating a screen D9 for a (second)notification that the security function is operated due to thecancellation of the apparatus connection, which is displayed in aprocessing of Step S45 of FIG. 11.

FIG. 27 is a front view illustrating a screen D10 for a (first)notification that the security function is operated because theapparatus connection is changed, which is displayed in a processing ofStep S31 of FIG. 10.

FIG. 28 is a front view illustrating a screen D11 for a (second)notification that the security function is operated because theapparatus connection is changed, which is displayed in a processing ofStep S35 of FIG. 10.

FIG. 29 is a front view illustrating an owner ID menu screen D12 after aPIN number is registered, which is displayed in a processing of Step S51of FIG. 12.

FIG. 30 is a front view illustrating an owner ID menu screen D13 at thetime when a wrong PIN number is inputted, which is displayed in aprocessing of Step S56 of FIG. 12.

FIG. 31 is a front view illustrating an owner ID menu screen D14 after aname, house number, postal code or the security function is changed,which is displayed in processings of Steps S65 to S68 of FIG. 13.

FIG. 32 is a front view illustrating an owner ID menu screen D15 afterthe name, house number, postal code or security function is changed,which is displayed in the processings of Steps S65 to S68 of FIG. 13.

FIG. 33 is a front view illustrating an owner ID menu screen D16 afterthe name, house number, or postal code is changed, which is displayed inprocessings of Steps S69 to S70 of FIG. 13.

FIG. 34 is a front view illustrating a screen D17 as an ordinarychannel-selecting screen, which is displayed in a processing of Step S10of FIG. 7.

DESCRIPTION OF REFERENCE SYMBOLS

-   201 . . . television receiver,-   202 . . . controller,-   203 . . . non-volatile memory,-   203A . . . ROM,-   204 . . . video signal and audio signal processor circuit,-   204A . . . display unit,-   205 . . . DVD recorder,-   206 . . . controller,-   207 . . . non-volatile memory,-   208 . . . video signal and audio signal processor circuit,-   208A . . . DVD drive apparatus,-   209 . . . apparatus control line,-   210 . . . video signal line,-   211 . . . audio signal line,-   220 . . . infra-red ray signal receiver,-   221 . . . remote controller,-   222 . . . keyboard, and-   223 . . . infra-red ray signal transmitter.

BEST MODE FOR CARRYING OUT AN INVENTION

Hereinafter, preferred embodiments according to the present inventionare described referring to the drawings.

FIG. 1 is a block diagram illustrating a configuration of a securitysystem including a television receiver 201 and a DVD recorder 205according to a preferred embodiment of the present invention. Thesecurity system according to the preferred embodiment includes thetelevision receiver 201 and the DVD recorder 205 connected to each othervia an apparatus control line 209. The DVD recorder 205 includes anon-volatile memory 207 previously storing a password. The televisionreceiver 201 includes a non-volatile memory 203 previously storing thepassword, and a controller 202. The controller 202 requests the DVDrecorder 205 to transmit the password stored in the non-volatile memory207 using a communication procedure P4 of FIG. 6 when the televisionreceiver 201 is activated or started up. The controller 202 receives thepassword from the DVD recorder 205. The controller 202 compares thereceived password with the password stored in the non-volatile memory203 (at Step S25 of FIG. 9). When the passwords coincide with each other(YES at Step S26), the controller 202 starts an operation of thetelevision receiver 201 (at Step S26A). In the present preferredembodiment, a PIN number (Personal Identification Number) is used as thepassword.

Referring to FIG. 1, the television receiver 201 as a main apparatusincludes the controller 202 for controlling the operation thereof, thenon-volatile memory 203 for storing data such as the PIN number as thepassword, for example, EEPROM, a flash memory or the like, a ROM(read-only memory) 203A for storing data such as a special PIN numberfor customer engineer, a video signal and audio signal processor circuit204, a display unit 204A, and an infra-red ray signal receiver 220 forreceiving an infra-red ray signal from an infra-red ray signaltransmitter 223 of a remote controller 221. The television receiver 201is additionally provided with the remote controller 221 used by a userto remotely control the operation of the television receiver 201. Theremote controller 221 includes a keyboard 222 for inputting data such asthe password and channel-selection data, and the infra-red ray signaltransmitter 223 for transmitting the inputted data to the infra-red raysignal receiver 220.

The DVD recorder 205 includes a controller 206 for controlling operationthereof, the non-volatile memory 203, such as the EEPROM, flash memoryor the like, which is connected to the controller 206 and stores thedata such as the PIN number as the password and information on whetheror not a security function is included, a video signal and audio signalprocessor circuit 208, and a DVD drive apparatus 208A. The controller202 of the television receiver 201 and the controller 206 of the DVDrecorder 205 are connected to each other via the apparatus control line209 used for controlling electronic apparatuses, such as a 21 pin skirtcable used in an electronic apparatus in Europe, HDMI (High DefinitionMultimedia Interface) cable and a control cable in compliance with IEEE1394. The controllers 202 and 206 transmit and receive various signalstherebetween using the communication procedures P1 to P4 described laterreferring to FIGS. 3 to 6. In the present preferred embodiment, theconnection using the apparatus control line 209 is referred to as “anapparatus connection”. The video signal and audio signal processorcircuit 204 and the video signal and audio signal processor circuit 208are connected to each other via a video signal line 210 and an audiosignal line 211. The video signal and audio signal processor circuit208, whose operation is controlled by the controller 206, executes apredetermined signal processing to a video signal and an audio signalreproduced in the DVD drive apparatus 208A, and then transmits the videoand audio signals to the video signal and audio signal processor circuit204 via the video signal line 210 and the audio signal line 211.

In the remote controller 221 additionally provided in the televisionreceiver 201, the keyboard 222 includes arrow keys including a centralkey, numeric keypad, functional keys and the like, for example, as shownon a screen D2 of FIG. 19. The user inputs the data such as the passwordand channel-selection information with the keyboard 222. The inputteddata is transmitted by radio to the infra-red ray signal receiver 220 bythe infra-red ray signal transmitter 223, and outputted to thecontroller 202. The data such as the PIN number stored in thenon-volatile memory 203 is read out by the controller 202, and the datasuch as the special PIN number stored in the ROM 203A is read out by thecontroller 202. The video signal and audio signal processor circuit 204,whose operation is controlled by the controller 202, receives the videosignal and the audio signal from the video signal and audio signalprocessor circuit 208, and executes a predetermined signal processingthereto. Then, the video signal and audio signal processor circuit 204outputs the signal-processed signals to the display unit 204A and aspeaker (not shown).

Referring to FIGS. 3 to 6, below are described various kinds ofcommunication procedures P1 to P4 executed between the controller 202 ofthe television receiver 201 used as the main apparatus and thecontroller 206 of the DVD recorder 205 as an auxiliary apparatus via theapparatus control line 209.

FIG. 3 is a sequence diagram illustrating the communication procedure P1between the controller 202 and the controller 206 of FIG. 1. In FIG. 3,the controller 202 transmits a connection confirmation signal to thecontroller 206. In response to the connection confirmation signal, thecontroller 206 transmits a connection confirmation ACK signal (ACK is anabbreviation for acknowledgement) to the controller 202 upon receivingthe connection confirmation signal. This leads to that the controller202 and the controller 206 can confirm that the apparatuses are normallyconnected via the apparatus control line 209.

FIG. 4 is a sequence diagram illustrating the communication procedure P2between the controller 202 and the controller 206 of FIG. 1. In FIG. 4,the controller 202 transmits a security function confirmation signal tothe controller 206. In response to the security function confirmationsignal, the controller 206 reads out information on whether or not theDVD recorder 205 has the security function from the non-volatile memory207. The controller 206 transmits a security function ACK signal to thecontroller 202 when the DVD recorder 205 has the security function. Onthe other hand, the controller 206 does not transmit the securityfunction ACK signal to the controller 202 when the DVD recorder 205 doesnot have the security function. This leads to that the controller 202and the controller 206 can confirm whether or not the DVD recorder 205has the security function.

FIG. 5 is a sequence diagram illustrating the communication procedure P3between the controller 202 and the controller 206 of FIG. 1. In FIG. 5,the controller 202 transmits a password write request signal includingthe password to be written to the controller 206. In response to thepassword write request signal, the controller 206 writes the passwordincluded in the password write request signal in the non-volatile memory207, and then, transmits a password write ACK signal to the controller202. This leads to that the password can be written in the non-volatilememory 207 from the controller 202 via the controller 206, and thecontroller 202 can confirms a result of the password writing.

FIG. 6 is a sequence diagram illustrating the communication procedure P4between the controller 202 and the controller 206 of FIG. 1. In FIG. 6,the controller 202 transmits the password request signal for requestingthe password stored in the non-volatile memory 207 to the controller206. In response to the password write request signal, the controller206 reads out the password stored in the non-volatile memory 207, andtransmits a password reply signal including the password to thecontroller 202. This leads to that the password stored in thenon-volatile memory 207 can be read out, and received from thecontroller 202 via the controller 206.

FIG. 7 is a flow chart illustrating a first processing executed by thecontroller 202 of FIG. 1 when a power supply is turned on aftershipment. In each control processing hereinafter, a screen is displayedon the display unit 204A. Each of Screens D1 to D17 illustrated in FIGS.18 to 34 shows an example.

Referring to FIG. 7, at Step S1, a screen D1 of FIG. 18 is displayed,and an automatic set-up processing including an automatic tuning presetprocessing is executed. At Step S2, the screen D2 of FIG. 19, which isan owner ID (Identification) screen serving as a user registrationscreen is displayed. Next, the user inputs user registration informationincluding the PIN number (four-digit figure), name, address, and postalcode on the screen D2 with the keyboard 222. At Step S4, the apparatusconnection is confirmed according to the communication procedure P1. AtStep S5, it is judged whether or not the apparatus connection is done.If YES at Step S5, the control flow proceeds to Step S6. On the otherhand, if NO at Step S5, the control flow proceeds to Step S10. At StepS6, the security function of the DVD recorder 205 used as the connectedapparatus is confirmed according to the communication procedure P2. AtStep S7, It is judged whether or not the connected apparatus includesthe security function. If YES at Step S7, the control flow proceeds toStep S8. On the other hand, if NO at Step S7, the control flow proceedsto Step S10. At Step S8, a screen for confirming use of the securityfunction (screen D3 of FIG. 20) is displayed. In a security functionconfirmation processing of Step S9 (FIG. 8), it is confirmed whether ornot the user wishes to use the security function, and the control flowproceeds to Step S10. The user selects YES on the screen D3 when theuser uses the security function. On the other hand, the user selects NOon the screen D3 when the user does not use the security function. AtStep 10, a program position “1” is selected on an ordinarychannel-selecting screen as shown on a screen D17 of FIG. 34, and then,the control flow is terminated. Then, an ordinary processing (forexample, Step S29 of FIG. 9) is executed.

In FIG. 7, when the apparatus connection is undone (NO at Step S5) orthe connected apparatus is not provided with the security function (NOat Step S7), the entry item relating to the security function is notdisplayed because the security function confirmation processing is notexecuted. Thus, the user is not notified of the presence of the securityfunction in the television receiver 201. This leads to that the user isnot provided with any unnecessary information, and the operation can besimplified.

FIG. 8 is a flow chart illustrating the security function confirmationprocessing (Step S9) which is a subroutine of FIG. 7.

In FIG. 8, at Step S11, it is judged whether or not the securityfunction is used. At Step S12, as shown on a screen D7 of FIG. 24, amessage indicating that the security function is not used is displayedfor two seconds, and a security flag SF is reset to 0. Then, the controlflow returns to a main routine. The security flag SF indicates that thesecurity function is used when set to 0. On the other hand, the securityflag SF indicates that the security function is not used when set to 1.At Step S14, a screen D4 for reconfirmation of the use of the securityfunction (FIG. 21) is displayed. If the use of the security function isaffirmatively reconfirmed, a screen D5 (FIG. 22) for re-reconfirmationof the use of the security function is displayed at Step S15. If the useof the security function is affirmatively re-reconfirmed, the controlflow proceeds to Step S16. At Step S16, the controller 206 is instructedto write the PIN number inputted at Step S3 in the non-volatile memory207 according to the communication procedure P3. Then, at Step S17, itis judged whether or not the password ACK signal was received, and theprocessing of Step S17 is repeated until YES is obtained at Step S17.When YES at Step S17, the PIN number is written in the non-volatilememory 203 at Step S18. At Step S19, a message indicating that thesecurity function is installed is displayed for two seconds as shown ona screen D6 of FIG. 23. The security flag SF is set to 1. Then thecontrol flow returns to the main routine.

FIGS. 9 to 11 are flow charts illustrating the apparatus controlprocessing executed by the controller 202 of FIG. 1.

At Step S21 of FIG. 9, the apparatus connection is confirmed accordingto the communication procedure P1. At Step S22, it is judged whether ornot the apparatus connection is done. If YES at Step S22, the controlflow proceeds to Step S23. On the other hand, if NO at Step S22, thecontrol flow proceeds to Step S41 of FIG. 11. At Step S23, the presenceor absence of the security function in the DVD recorder 205 used as theconnected apparatus is confirmed according to the communicationprocedure P2. At Step S24, it is judged whether or not the securityfunction is included. If YES at Step S24, the control flow proceeds toStep S25. On the other hand, if NO at Step S24, the control flowproceeds to Step S31 of FIG. 10. At Step S25, the transmission of thePIN number stored in the non-volatile memory 207 is requested accordingto the communication procedure P4, and the PIN number is received fromthe controller 206 via the apparatus control line 209, and the receivedPIN number is compared with the PIN number stored in the non-volatilememory 203. At Step S26, it is judged whether or not the PIN numberscoincide with each other. If YES at Step S26, the control flow proceedsto Step S26A. On the other hand, if NO at Step S26, the control flowproceeds to Step S31 of FIG. 10. At Step S26A, the operation of thevideo signal and audio signal processor circuit 204 is started, or anoperable state is maintained. At Step S27, it is judged whether or notthe owner ID menu has been selected on a predetermined menu screen. IfYES at Step S27, the control flow proceeds to Step S28. On the otherhand, if NO at Step S27, the control flow proceeds to Step S29. At StepS28, an owner ID re-registration processing of FIGS. 12 to 14 isexecuted, and the control flow returns to Step S21. At Step S29, theother ordinary processing is executed. Then the control flow returns toStep S21.

At Step S31 of FIG. 10, a message indicating that the connectedapparatus is changed is displayed as shown on a screen D10 of FIG. 27.The user is instructed to input the PIN number (four-digit figure) inorder to cancel the security function. At Step S32, it is judged whetheror not the PIN number has been inputted. If YES at Step S32, the controlflow proceeds to Step S33. On the other hand, if NO at Step S32, thecontrol flow returns to Step S32. At Step S33, The inputted Pin numberand the PIN number stored in the non-volatile memory 203 are comparedwith each other. At Step S34, it is judged whether or not the PINnumbers coincide with each other. If YES at Step S34, the control flowproceeds to Step S36. On the other hand, if NO at Step S34, the controlflow proceeds to Step S35. At Step S35, the operation of the videosignal and audio signal processor circuit 204 is stopped, and it isdisplayed and notified that the PIN number is incorrect as shown on ascreen D11 of FIG. 28. Then, the input of the PIN number is requestedagain. The control flow then returns to Step S32. At Step S36, theoperation of the video signal and audio signal processor circuit 204 isstarted. At Step S37, the security flag is reset to 0 so as to cancelthe security function. Then, the control flow proceeds to Step S29 ofFIG. 9.

At Step S41 of FIG. 11, a message indicating that the security functionis operated is displayed, as shown on a screen D8 of FIG. 25, becausethe connected apparatus is separated. The user is instructed to inputthe PIN number when the user wishes to cancel the security function. AtStep S42, it is judged whether or not the PIN number has been inputted.If YES at Step S42, the control flow proceeds to Step S43. On the otherhand, if NO at Step S42, the control flow returns to Step S42. At StepS43, the inputted PIN number and the PIN number stored in thenon-volatile memory 203 are compared with each other. At Step S44, it isjudged whether or not the PIN numbers coincide with each other. If YESat Step S44, the control flow proceeds to Step S46. On the other hand,if NO at Step S44, the control flow proceeds to Step S45. At Step S45,the operation of the video signal and audio signal processor circuit 204is stopped, and it is displayed and notified that the PIN number isincorrect, as shown on a screen D9 of FIG. 26. Then, the input of PINnumber is requested again. The control flow returns to Step S42. At StepS46, the operation of the video signal and audio signal processingcircuit 204 is started. At Step S47, the security flag SF is reset to 0so as to cancel the security function. The control flow then proceeds toStep S29 of FIG. 9.

FIGS. 12 to 14 are flow charts of a processing executed when the owneris ID re-registered (Step S28) which is a subroutine of FIG. 9.

At Step S51 of FIG. 12, the owner ID menu is displayed, as shown on ascreen D12 of FIG. 29. At Step S52, the user is instructed to input thePIN number (four-digit figure). At Step S53, it is judged whether or notthe PIN number has been inputted. If YES at Step S53, the control flowproceeds to Step S54. On the other hand, if NO at Step S53, the controlflow returns to Step S53. At Step S54, The inputted PIN number and thePIN number stored in the non-volatile memory 203 are compared with eachother. At Step S55, It is judged whether or not the PIN numbers coincidewith each other. If YES at Step S55, the control flow proceeds to StepS57. On the other hand, if NO at Step S55, the control flow proceeds toStep S56A. At Step S56A, it is judged whether or not the security flagis 1, that is, it is judged whether or not the security function is set.If YES at Step S56A, the control flow proceeds to Step S56B. On theother hand, if NO at Step S56A, the control flow proceeds to Step S56C.At Step S56B, the operation of the video signal and audio signalprocessor circuit 204 is stopped. At Step S56C, it is displayed andnotified that the PIN number is incorrect as shown on a screen D13 ofFIG. 30. Then, the input of the PIN number is requested again. Thecontrol flow then returns to Step S53. At Step S57, the operation of thevideo signal and audio signal processor circuit 204 is started. Then,the control flow proceeds to Step S61 of FIG. 13.

The apparatus connection is confirmed according to the communicationprocedure P1 at Step S61 of FIG. 13. At Step S62, it is judged whetheror not the apparatus connection is done. If YES at Step S62, the controlflow proceeds to Step S63. On the other hand, if NO at Step S62, thecontrol flow proceeds to Step S69. At Step S63, the presence or absenceof the security function in the DVD recorder 205 is confirmed accordingto the communication procedure P2. At Step S64, it is judged whether ornot the security function is included. If YES at Step S64, the controlflow proceeds to Step S65. On the other hand, if NO at Step S64, thecontrol flow proceeds to Step S69. At Step S65, the item of the“security function” is added to the owner ID menu and displayed, asshown on a screen D14 of FIG. 31. At Step S66, the PIN number, name,address and postal code are re-registered in the owner ID menu. At StepS67, the current value of the security flag SF is saved in a savesecurity flag SF1. Further, at Step S68, the ON or OFF of the securityfunction is selected on the screen D14 or D15. The screen D14 shows thatthe security function is turned off. The screen D15 shows that thesecurity function is turned on. When the security function is turned on,1 is set to the security flag SF. The security flag SF is reset to 0when the security function is turned off. Then, the control flowproceeds to Step S72 of FIG. 14.

At Step S69 of FIG. 13, the item of the “security function” is notdisplayed on the owner ID menu, as shown on a screen D16 of FIG. 33. AtStep S70, the PIN number, name, address and postal code arere-registered on the owner ID menu. At Step S71, the security flag SF isreset to 0. Then, the other ordinary processing at Step S29 of FIG. 9 isexecuted.

Referring to FIG. 13, when the apparatus connection is undone (NO atStep S62) or the connected apparatus is not provided with the securityfunction (NO at Step S64), the entry item relating to the securityfunction is not displayed because the security function confirmationprocessing is not executed. The user is not notified of the presence ofthe security function in the television receiver 201. This leads to thatthe user is not provided with any unnecessary information, and theoperation can be simplified.

At Step S72 of FIG. 14, it is judged whether or not SF1=0 and SF=1, thatis, it is judged whether or not the setting of the security functionshifts from OFF to ON. If YES at Step S72, the control flow proceeds toStep S14 of FIG. 8. On the other hand, if NO at Step S72, the controlflow proceeds to Step S73. At Step S73, it is judged whether or notSF1=1 and SF=0, that is, it is judged whether or not the setting of thesecurity function shifts from ON to OFF. If YES at Step 73, the controlflow proceeds to Step S12 of FIG. 8. On the other hand, if NO at Step73, the control flow proceeds to the other ordinary processing at StepS29 of FIG. 9.

FIG. 15 is a flow chart illustrating a modified example of theprocessing of FIG. 10. FIG. 16 is a flow chart illustrating a modifiedexample of the processing of FIG. 11. FIG. 17 is a flow chartillustrating a modified example of the processing of FIG. 12. Themodified examples of FIGS. 15 to 17 are characterized in that there hasbeen added the processing that the special PIN number for customerengineer previously stored in the ROM 203A is judged to be identical,and the processing that the operation of the video signal and audiosignal processor circuit 204 is stopped when a PIN number is inputted atleast a predetermined number of times N (for example, N is three) andstill fails to be identical. The special PIN number is previously storedin the ROM 203A. The special PIN number is provided so that the securityfunction is forcibly cancelled when a manufacturer or a person assignedby the manufacturer, such as a customer engineer, inputs the special PINnumber as the password for canceling the security function other thanthe PIN number inputted by the user, and the operation of the televisionreceiver 201 is started.

The modified example of FIG. 15 is characterized in that processings ofSteps S38 to S35B are inserted between Step S34 and Step S32. If NO atStep S34, the inputted PIN number and the special PIN number stored inthe ROM 203A are compared with each other at Step S38. At Step S39, itis judged whether or not the PIN numbers coincide with each other. IfYES at Step S39, the control flow proceeds to Step S36. On the otherhand, if NO at Step S39, the control flow proceeds to Step S40. At StepS40, it is judged whether or not the PIN number is inputted at least thepredetermined number of times N and still fails to be identical. If YESat Step S40, the control flow proceeds to Step S35A. On the other hand,if NO at Step S40, the control flow proceeds to Step S35B. At Step S35A,the operation of the video signal and audio signal processor circuit 204is stopped. At Step S35B, it is displayed and notified that the PINnumber is incorrect, as shown on a screen D11 of FIG. 28. The input ofthe PIN number is requested again. Then, the control flow proceeds toStep S32.

The modified example of FIG. 16 is characterized in that processings ofSteps S48 to S45B are inserted between Step S44 and Step S42. If NO atStep S44, the inputted PIN number and the special PIN number stored inthe ROM 203A are compared with each other at Step S48. At Step S49, itis judged whether or not the PIN numbers coincide with each other. IfYES at Step S49, the control flow proceeds to Step S46. On the otherhand, if NO at Step S49, the control flow proceeds to Step S50. At StepS50, it is judged whether or not the PIN number is inputted at least thepredetermined number of times N and still fails to be identical. If YESat Step S50, the control flow proceeds to Step S45A. On the other hand,if NO at Step S50, the control flow proceeds to Step S45B. At Step S45A,the operation of the video signal and audio signal processor circuit 204is stopped. At Step S45B, it is displayed and notified that the PINnumber is incorrect, as shown on a screen D9 of FIG. 26. The input ofthe PIN number is requested again. Then, the control flow proceeds toStep S42.

The modified example of FIG. 17 is characterized in that processings ofSteps S58 to S56C are inserted between Step S55 and Step S53. If NO atStep S55, the inputted PIN number and the special PIN number stored inthe ROM 203A are compared with each other at Step S58. At Step S59, itis judged whether or not the PIN numbers coincide with each other. IfYES at Step S59, the control flow proceeds to Step S57. On the otherhand, if NO at Step S59, the control flow proceeds to Step S56A. At StepS56A, it is judged whether or not the security flag SF is 1, that is, itis judged whether or not the security function is set. If YES at StepS56A, the control flow proceeds to Step S60. On the other hand, if NO atStep S56A, the control flow proceeds to Step S56C. In the S60, it isjudged whether or not the PIN number is inputted at least thepredetermined number of times N and still fails to be identical. If YESat Step S60, the control flow proceeds to Step S56B. On the other hand,if NO at Step S60, the control flow proceeds to Step S56C. At Step S56B,the operation of the video signal and audio signal processor circuit 204is stopped. At Step S56C, it is displayed and notified that the PINnumber is incorrect, as shown on the screen D11 of FIG. 28. The input ofthe PIN number is requested again. Then, the control flow proceeds toStep S53.

In the foregoing preferred embodiments, the security system includingthe television receiver 201 and the DVD recorder 205 is disclosed.However, the present invention is not limited to the configuration. Theelectronic apparatuses used in the security system are not limited tothe mentioned apparatuses. Various kinds of electronic apparatuses, suchas a television receiving apparatus, a set-top box, a display apparatus,a DVD player or the like, may be used. Further, at least threeelectronic apparatuses may be connected via the apparatus control line209 to constitute the security system.

In the foregoing preferred embodiments, the data inputted by the userwith the keyboard 222 is transmitted by radio to the controller 202using the infra-red ray signal. However, the present invention is notlimited thereto. The keyboard 222 may be provided in a main body of thetelevision receiver 201.

In the foregoing preferred embodiments, if NO at Step S26 of FIG. 9, thecontrol flow proceeds to Step S31 of FIG. 10. However, the presentinvention is not limited thereto. “A processings for stopping theoperation of the video signal and audio signal processor circuit 204”,which is a part of Step S35, may be executed prior to the advancement toStep S31.

INDUSTRIAL APPLICABILITY

As described in detail so far, according to the security system for usein the electronic apparatus of the present invention, the password isregistered in the storage means of the electronic apparatus used as theconnected auxiliary apparatus in the security system for use in theplurality of electronic apparatuses connected via the apparatus controlline so that the password can be confirmed when the electronic apparatusused as the main apparatus is activated or started up. As far as theapparatus control line is connected, when the passwords coincide witheach other between the electronic apparatus used as the main apparatusand the electronic apparatus used as the auxiliary apparatus, the usercan activate the electronic apparatus in a manner similar to that of theprocessing usually executed when the power supply is turned on. Theelectronic apparatus used as the main apparatus cannot be activated orstarted up when the electronic apparatus used as the auxiliary apparatusis not connected. As a result, even if the electronic apparatus used asthe main apparatus is stolen, it is not possible to activate the same.Accordingly, the theft can be prevented without forcing the user intosuch a bothersome operation as the input of the password. Further, thesystem according to the present invention can be effectively realizedwithout increasing the cost.

1-18. (canceled)
 19. A security system for use in a plurality ofelectronic apparatuses including a first electronic apparatus and asecond electronic apparatus connected to each other via an apparatuscontrol line, wherein the second electronic apparatus comprises a secondstorage device for previously storing a password, and wherein the firstelectronic apparatus comprises: a first storage device for previouslystoring the password; and a control device for requesting the secondelectronic apparatus to transmit the password stored in the secondstorage device at activation of the first electronic apparatus,receiving the password from the second electronic apparatus, comparingthe received password with the password stored in the first storagedevice, and executing a security function so as to start an operation ofthe first electronic apparatus when the passwords coincide with eachother.
 20. The security system as claimed in claim 19, wherein thecontrol device compares the received password with the password storedin the first storage device, and executes the security function so as tostop the operation of the first electronic apparatus when the passwordsdo not coincide with each other.
 21. The security system as claimed inclaim 19, wherein the first electronic apparatus further comprises: adisplay device for displaying a message to a user; and an input devicefor inputting the password, and wherein the control device compares thereceived password with the password stored in the first storage device,displays a request of inputting the password to a user on the displaydevice when the passwords do not coincide with each other, compares thepassword inputted by the user using the input device with the passwordstored in the first storage device, and starts the operation of thefirst electronic apparatus when the passwords coincide with each other.22. The security system as claimed in claim 21, wherein the controldevice compares the password inputted by the user with the passwordstored in the first storage device, and stops the operation of the firstelectronic apparatus when the passwords do not coincide with each other.23. The security system as claimed in claim 21, wherein the controldevice compares the password inputted by the user a predetermined numberof times of more than two with the password stored in the first storagedevice, and stops the operation of the first electronic apparatus whenthe passwords do not coincide with each other.
 24. The security systemas claimed in any one of claim 21, wherein the first electronicapparatus further comprises a third storage device for previouslystoring a special password other than the password, and wherein thecontrol device compares the inputted password with the special passwordstored in the third storage device, and starts the operation of thefirst electronic apparatus when the passwords coincide with each other.25. The security system as claimed in claim 19, wherein the firstelectronic apparatus further comprises: a first detecting device fordetecting whether or not the second electronic apparatus is connected tothe first electronic apparatus via the apparatus control line; and asecond detecting device for detecting whether or not the secondelectronic apparatus has the security function using a control signal ofthe apparatus control line when the first detecting device detects thatthe second electronic apparatus is connected to the first electronicapparatus, and wherein the control device executes the processings ofthe first detecting device and the second detecting device duringoperation of the first electronic apparatus.
 26. The security system asclaimed in claim 25, wherein the control device stops the processing ofthe security function, and starts an ordinary operation of the firstelectronic apparatus when the first detecting device detects that thesecond electronic apparatus is not connected to the first electronicapparatus.
 27. The security system as claimed in claim 26, wherein thecontrol device stops the processing of the security function, and startsthe ordinary operation of the first electronic apparatus when the seconddetecting device detects that the second electronic apparatus does nothave the security function.
 28. A first electronic apparatus provided ina security system for use in a plurality of electronic apparatusesincluding a first electronic apparatus and a second electronic apparatusconnected to each other via an apparatus control line, wherein thesecond electronic apparatus comprises a second storage device forpreviously storing a password, and wherein the first electronicapparatus comprises: a first storage device for previously storing thepassword; and control device for requesting the second electronicapparatus to transmit the password stored in the second storage device,receiving the password from the second electronic apparatus when thefirst electronic apparatus is activated or started up, comparing thereceived password with the password stored in the first storage device,and executing a security function so as to start an operation of thefirst electronic apparatus when the passwords coincide with each other.29. The electronic apparatus for a security system as claimed in claim28, wherein the control device compares the received password with thepassword stored in the first storage device, and executes the securityfunction so as to stop the operation of the first electronic apparatuswhen the passwords do not coincide with each other.
 30. The electronicapparatus for a security system as claimed in claim 28, wherein thefirst electronic apparatus further comprises: a display device fordisplaying a message to a user; and an input device for inputting thepassword, and wherein the control device compares the received passwordwith the password stored in the first storage device, displays a requestof inputting the password to a user on the display device when thepasswords do not coincide with each other, compares the passwordinputted by the user using the input device with the password stored inthe first storage device, and starts the operation of the firstelectronic apparatus when the passwords coincide with each other. 31.The electronic apparatus for a security system as claimed in claim 30,wherein the control device compares the password inputted by the userwith the password stored in the first storage device, and stops theoperation of the first electronic apparatus when the passwords do notcoincide with each other.
 32. The electronic apparatus for a securitysystem as claimed in claim 30, wherein the control device compares thepassword inputted by the user a predetermined number of times of morethan two with the password stored in the first storage device, and stopsthe operation of the first electronic apparatus when the passwords donot coincide with each other.
 33. The electronic apparatus for asecurity system as claimed in claim 30, wherein the first electronicapparatus further comprises a third storage device for previouslystoring a special password other than the password, and wherein thecontrol device compares the inputted password with the special passwordstored in the third storage device, and starts the operation of thefirst electronic apparatus when the passwords coincide with each other.34. The electronic apparatus for a security system as claimed in claim28, wherein the first electronic apparatus further comprises: a firstdetecting device for detecting whether or not the second electronicapparatus is connected to the first electronic apparatus via theapparatus control line; and a second detecting device for detectingwhether or not the second electronic apparatus has the security functionusing a control signal of the apparatus control line when the firstdetecting device detects that the second electronic apparatus isconnected to the first electronic apparatus, and wherein the controldevice executes the processings of the first detecting device and thesecond detecting device during activation of the first electronicapparatus.
 35. The electronic apparatus for a security system as claimedin claim 34, wherein the control device stops the processing of thesecurity function, and starts an ordinary operation of the firstelectronic apparatus when the first detecting device detects that thesecond electronic apparatus is not connected to the first electronicapparatus.
 36. The electronic apparatus for a security system as claimedin claim 35, wherein the control device stops the processing of thesecurity function, and starts the ordinary operation of the firstelectronic apparatus when the second detecting device detects that thesecond electronic apparatus does not have the security function.